IEC/IEEE 60079-30-2:2015

Explosive atmospheres - Part 30-2: Electrical resistance trace heating - Application guide for design, installation and maintenance

IEC/IEEE 60079-30-2:2015 provides guidance for the application of electrical resistance trace heating systems in areas where explosive atmospheres may be present, with the exclusion of those classified as requiring EPL Ga/Da (traditional relationship to Zone 0 and Zone 20 respectively). This standard also provides guidance for explosive atmospheres incorporating the Division method of area classification that may be applied by some users of this standard. It provides recommendations for the design, installation, maintenance and repair of trace heating systems including associated control and monitoring equipment. It does not cover devices that operate by induction heating, skin effect heating or direct pipeline heating, nor those intended for stress relieving. This first edition of IEC/IEEE 60079-30-2 cancels and replaces the first edition of IEC 60079-30-2 published in 2007 and constitutes a technical revision. This edition includes the following significant changes, apart from a general review and updating of the first edition of IEC 60079-30-2, harmonization with IEEE Std.515, with respect to the previous edition:
- the relocation of trace heater product design methodology and requirements to IEC/IEEE 60079-30-1;
- the relocation and/or duplication of information on installation, maintenance, and repair to the MTs under SC31J for their addition into IEC 60079-14, IEC 60079-17, and IEC 60079-19;
- the inclusion of more detailed information on safety showers and eyewash units;
- the introduction of Annexes from IEEE Std. 515. Please refer to the Foreword of the document for the significance of changes between IEC 60079-30-2, Edition 1.0 (2007) and IEC/IEEE 60079-30-2, Edition 1.0 (2014). Keywords: electrical resistance trace heating systems, Division method of area classification

Atmosphères explosives - Partie 30-2: Traçage par résistance électrique - Guide d'application pour la conception, l'installation et la maintenance.

IEC/IEEE 60079-30-2:2015 fournit des lignes directrices pour l'application des systèmes de traçage par résistance électrique dans les emplacements où des atmosphères explosives peuvent être présentes, à l’exception de ceux classés comme exigeant l'EPL Ga/Da (relation traditionnelle à la Zone 0 et la Zone 20, respectivement). La présente norme donne également des lignes directrices relatives aux atmosphères explosives intégrant la méthode de classement des emplacements par division qui peut être appliquée par certains utilisateurs de la présente norme. Elle fournit des recommandations pour la conception, l'installation, la maintenance et la réparation des systèmes de traçage, y compris le matériel associé de commande et de surveillance. Elle ne couvre pas les dispositifs qui fonctionnent par chauffage par induction, chauffage à effet de peau ou chauffage par impédance, ni ceux destinés au relâchement des contraintes. Cette première édition de l'IEC/IEEE 60079-30-2 annule et remplace la première édition de l'IEC 60079-30-2 parue en 2007. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes, hormis la révision générale et la mise à jour de la première édition de l'IEC 60079-30-2 et de l'harmonisation avec la norme IEEE 515, par rapport à l'édition précédente:
- déplacement de la méthode de conception des résistances de traçage et des exigences dans l'IEC/IEEE 60079-30-1;
- déplacement et/ou reproduction des informations relatives à l'installation, la maintenance et la réparation à l’intention des équipes de maintenance (MT) relevant du SC31J, dans l'IEC 60079-14, l'IEC 60079-17 et l'IEC 60079-19;
- introduction d'informations plus détaillées relatives aux douches de sécurité et aux bassins oculaires;
- introduction des Annexes issues de la norme IEEE 515.
Référence à l'avant-propos du document concernant l'importance des modifications entre la CEI 60079-30-2, édition 1.0 (2007) et la CEI / IEEE 60079-30-2, édition 1.0 (2014)

General Information

• Status: Published
• Publication Date: 27-Sep-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: TC 31 - Equipment for explosive atmospheres
• Current Stage: PPUB - Publication issued
• Start Date: 28-Sep-2015
• Completion Date: 28-Sep-2015

Standards Content (sample)

IEC/IEEE 60079-30-2
Edition 1.0 2015-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 30-2: Electrical resistance trace heating – Application guide for design,
installation and maintenance
Atmosphères explosives –
Partie 30-2: Traçage par résistance électrique – Guide d'application pour la
conception, l'installation et la maintenance
IEC/IEEE 60079-30-2:2015-09 (en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
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---------------------- Page: 2 ----------------------
IEC/IEEE 60079-30-2
Edition 1.0 2015-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 30-2: Electrical resistance trace heating – Application guide for design,
installation and maintenance
Atmosphères explosives –
Partie 30-2: Traçage par résistance électrique – Guide d'application pour la
conception, l'installation et la maintenance
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-5200-0

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC/IEEE 60079-30-2:2015
© IEC/IEEE 2015
CONTENTS

FOREWORD ........................................................................................................................... 6

1 Scope ............................................................................................................................ 10

2 Normative references .................................................................................................... 10

3 Terms and definitions .................................................................................................... 10

4 Application considerations ............................................................................................. 10

4.1 General ................................................................................................................. 10

4.2 Corrosive areas .................................................................................................... 11

4.3 Process temperature accuracy .............................................................................. 11

4.3.1 Type I ............................................................................................................ 11

4.3.2 Type II ........................................................................................................... 11

4.3.3 Type III .......................................................................................................... 11

4.4 Installation considerations ..................................................................................... 11

5 Thermal insulation ......................................................................................................... 12

5.1 General ................................................................................................................. 12

5.2 Selection of insulating material ............................................................................. 12

5.3 Selection of weather barrier (cladding) .................................................................. 13

5.4 Selection of economical thickness to provide optimum trace heating design.......... 13

5.5 Double insulation .................................................................................................. 14

6 System design ............................................................................................................... 17

6.1 General ................................................................................................................. 17

6.2 Purpose of, and major requirement for, trace heating ............................................ 17

6.3 Training ................................................................................................................ 18

6.4 Selection of trace heater ....................................................................................... 18

6.4.1 General ......................................................................................................... 18

6.4.2 Site-fabricated trace heaters .......................................................................... 18

6.4.3 Specific types of trace heating ....................................................................... 19

6.5 Maximum temperature determination .................................................................... 19

6.5.1 General ......................................................................................................... 19

6.5.2 PTC characteristic ......................................................................................... 19

6.5.3 Stabilized design ........................................................................................... 20

6.5.4 Controlled design........................................................................................... 20

6.6 Heat up and cool down considerations .................................................................. 20

6.7 Design information ................................................................................................ 20

6.7.1 Design information documentation ................................................................. 20

6.7.2 Isometric or trace heater configuration line lists and load charts .................... 21

6.8 Power system ....................................................................................................... 22

6.9 Earthing requirements ........................................................................................... 22

6.10 Earth-fault protection of equipment ....................................................................... 23

6.11 Start-up at minimum ambient temperatures ........................................................... 23

6.12 Long trace heater runs .......................................................................................... 23

6.13 Flow pattern analysis ............................................................................................ 23

6.14 Dead-leg control technique ................................................................................... 25

6.15 Chimney effect ...................................................................................................... 25

6.16 Safety shower and eyewash station design requirements ...................................... 26

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IEC/IEEE 60079-30-2:2015 – 3 –
© IEC/IEEE 2015

7 Control and monitoring .................................................................................................. 26

7.1 General ................................................................................................................. 26

7.2 Mechanical controllers .......................................................................................... 27

7.3 Electronic controllers ............................................................................................ 27

7.4 Application suitability ............................................................................................ 27

7.5 Location of controllers ........................................................................................... 27

7.6 Location of sensors ............................................................................................... 28

7.7 Alarm considerations ............................................................................................ 28

7.7.1 General ......................................................................................................... 28

7.7.2 Trace heating circuit alarm ............................................................................ 28

7.7.3 Temperature alarms ...................................................................................... 29

7.7.4 Other alarms .................................................................................................. 29

7.7.5 Integrated control .......................................................................................... 29

8 Recommendations for installation .................................................................................. 29

8.1 General ................................................................................................................. 29

8.2 Preparatory work .................................................................................................. 30

8.2.1 General ......................................................................................................... 30

8.2.2 Scheduling and coordination .......................................................................... 30

8.2.3 Confirmation of equipment ............................................................................. 30

8.2.4 Receiving materials ....................................................................................... 30

8.2.5 Warehousing and handling ............................................................................ 30

8.2.6 Personnel aspects ......................................................................................... 30

8.3 Installation of trace heating circuits ....................................................................... 30

8.3.1 Coordination and equipment verification ........................................................ 30

8.3.2 Pre-installation testing and design verification ............................................... 31

8.3.3 Visual examination ........................................................................................ 31

8.3.4 Insulation resistance test ............................................................................... 31

8.3.5 Component substitution ................................................................................. 31

8.3.6 Location of power supply ............................................................................... 31

8.3.7 Installation of trace heaters ........................................................................... 32

8.3.8 Connections and terminations ........................................................................ 34

8.4 Installation of control and monitoring equipment ................................................... 36

8.4.1 General ......................................................................................................... 36

8.4.2 Verification of equipment suitability................................................................ 36

8.4.3 Temperature controller and monitoring devices .............................................. 36

8.4.4 Sensor considerations ................................................................................... 36

8.4.5 Controller operation, calibration, and access ................................................. 40

8.4.6 Necessary modifications ................................................................................ 40

8.5 Installation of thermal insulation system (see also Clause 5) ................................. 40

8.5.1 General ......................................................................................................... 40

8.5.2 Preparatory work ........................................................................................... 40

8.5.3 Installation of the thermal insulation materials ............................................... 40

8.5.4 Cladding ........................................................................................................ 41

8.5.5 Field (site work) circuit insulation resistance test ........................................... 41

8.5.6 Visual inspection ........................................................................................... 41

8.5.7 Documentation .............................................................................................. 42

8.6 Installation of distribution wiring and coordination with branch circuits .................. 42

8.6.1 General ......................................................................................................... 42

8.6.2 Earth-fault protective device .......................................................................... 42

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© IEC/IEEE 2015

8.6.3 Circuit protective device ................................................................................ 42

8.6.4 Tagging/Identification .................................................................................... 42

8.7 Commissioning ..................................................................................................... 42

8.7.1 Pre-commissioning check .............................................................................. 42

8.7.2 Functional check and final documentation...................................................... 43

9 Maintenance .................................................................................................................. 44

9.1 General ................................................................................................................. 44

9.2 Fault location ........................................................................................................ 44

9.3 Fault rectification .................................................................................................. 44

10 Repairs .......................................................................................................................... 45

10.1 General ................................................................................................................. 45

10.2 Practicability of repair to electric trace heaters ...................................................... 45

10.2.1 Mechanical damage ....................................................................................... 45

10.2.2 Damage due to corrosion ............................................................................... 45

10.2.3 Damage due to overheating ........................................................................... 45

10.3 Repair techniques for electrical trace heaters ....................................................... 45

10.3.1 General ......................................................................................................... 45

10.3.2 In-line splice .................................................................................................. 46

10.3.3 Connection via junction box ........................................................................... 46

10.4 Earthing ................................................................................................................ 46

10.5 Testing ................................................................................................................. 46

Annex A (informative) Example of design data record .......................................................... 47

Annex B (informative) Checklist for installation requirements ............................................... 48

Annex C (informative) Example of trace heater commissioning record ................................. 49

Annex D (informative) Example of maintenance schedule and log record ............................. 50

Annex E (informative) Pipe heat loss considerations – Heat loss formula and example

calculations ........................................................................................................................... 51

Annex F (informative) Vessel heat loss considerations ......................................................... 57

F.1 General ................................................................................................................. 57

F.2 Insulation heat loss (Q ) ..................................................................................... 57

ins

F.3 Slab surface areas (Q ) .................................................................................... 58

slab

F.4 Support heat loss (Q ) ..................................................................................... 59

supt

F.5 Manhole heat loss (Q ) .............................................................................. 59

manhole

F.6 Convection coefficient formulae ............................................................................ 59

F.6.1 General ......................................................................................................... 59

F.6.2 Free convection, nonfluid surface, any orientation (h , h , h ) ...................... 59

i co o

F.6.3 Forced convection, any orientation (h ) ......................................................... 60

F.6.4 Radiation component, all coefficients (h , h , h , h ) ..................................... 61

f i co o

Annex G (informative) Heat up and cool down considerations .............................................. 62

G.1 Heat up ................................................................................................................. 62

G.2 Cool down ............................................................................................................. 63

Annex H (informative) Method to determine equivalent thicknesses of insulating

cements ................................................................................................................................ 65

Bibliography .......................................................................................................................... 66

Figure 1 – Thermal insulation – Weather-barrier installation .................................................. 15

Figure 2 – Typical temperature profile ................................................................................... 16

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IEC/IEEE 60079-30-2:2015 – 5 –
© IEC/IEEE 2015

Figure 3 – Flow pattern analysis example ............................................................................. 24

Figure 4 – Bypass example ................................................................................................... 25

Figure 5 – Typical installation of control sensor and sensor for temperature limiting

control .................................................................................................................................. 38

Figure 6 – Limiting device sensor on sheath of trace heater .................................................. 38

Figure 7 – Limiting device sensor as artificial hot spot .......................................................... 39

Figure E.1 – Assumed temperature gradients ....................................................................... 52

Table 1 – Pre-installation checks .......................................................................................... 32

Table A.1 – Example of design data record ........................................................................... 47

Table B.1 – Example of pre-commissioning check and trace heater installation record .......... 48

Table C.1 – Example of trace heater commissioning record .................................................. 49

Table D.1 – Example of maintenance schedule and log record.............................................. 50

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– 6 – IEC/IEEE 60079-30-2:2015
© IEC/IEEE 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 30-2: Electrical resistance trace heating –
Application guide for design, installation and maintenance
FOREWORD

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IEC/IEEE 60079-30-2:2015 – 7 –
© IEC/IEEE 2015

International Standard IEC/IEEE 60079-30-2 has been prepared by IEC technical committee

31: Equipment for explosive atmospheres, in cooperation with the Petroleum & Chemical

Industry Committee of the IEEE Industrial Applications Society under the IEC/IEEE Dual Logo

Agreement.
NOTE A list of IEEE participants can be found at the following URL:

http://standards.ieee.org/downloads/60079/60079-30-2-2015/60079-30-2-2015_wg-participants.pdf.

This first edition of IEC/IEEE 60079-30-2 cancels and replaces the first edition of IEC 60079-

30-2 published in 2007 and constitutes a technical revision.

This edition includes the following significant changes, apart from a general review and

updating of the first edition of IEC 60079-30-2, harmonization with IEEE Std 515, with respect

to the previous edition:

• the relocation of trace heater product design methodology and requirements to IEC/IEEE

60079-30-1;

• the relocation and/or duplication of information on installation, maintenance, and r

...